Manifold machining

[big job]

Interesting, we only get only $20 for a cleanup. This one is a Y block.

[RockHillWill]

From my perspective, no one here is questioning any ones abilities, only pointing out details that need to be attended to depending on which method that you decide is best for you. I was sharing my two poor results from the time I sent my manifolds out to others as the reason I decided to do things myself.

Those that know me, know that I DO 'over engineer' things and I am a vociferous tool collector. That is how I enjoy this hobby! I have been this way for a long time, after I heard Vince Lombardi's response to Bart Starr when Bart asked the coach how he was going to run the team.

Mr. Lombardi said " I am going to constantly charge you with the relentless pursuit of perfection, knowing that perfection is unobtainable but in the pursuit of perfection, you will pass thru excellence."

That is just my approach, others are free to choose their own methods in obtaining what ever level of work that they are satisfied with. It's all about details.

[Brentwood Bob]

No critcism implied ao intended by my comments. Bob

[Terry,NJ]

Same here! No one knows what the other person's abilities are. People make some rather good chainsaw cravings, but I couldn't do it. And I could never run a vertical "Up" or overhead pass with a stick welder. It just isn't my thing! Can't do it ! However, There's plenty of folks who can. More power to them!
Terry

[Purdy Swoft]

There was NO criticism meant by any of my posts on this thread either.

[Kohnke Rebabbitting]

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Originally Posted by RockHillWill

Just for general information, I am posting a fixture that I made to do my own 'match milling' after I had a number of poorly done efforts at automotive shops. If you are not careful to make the carb mounting surface perpendicular to the manifold sedge when you match mill the intake and exhausts together. tha combination will not be vertical when installed and not fit the RS engine pan or fit the flare on the exhaust very well. Hand held grinding was NEVER correct when done for me that way.

In addition. I did NOT want a real smooth gasket surface as it makes the gasket easier to 'squirrel it's way out of the edges. I chose to use a fly cutter and adjusted the feed speed to leave just a very minor 'irregularity' so that the gasket would have a grip to the manifolds.

As always, this is just a thought.

Attachment 156129

Attachment 156130

Attachment 156131

Good Job!!

[Pete]

Originally Posted by forever4

I have had one done on an automotive machine shop belt sander. The guy came recommended. He thought he created the Mona Lisa. I thought he created Marge Simpson. Never again a belt sander.

Belt sanders equate to having heart surgery done by your dentist.

[Kohnke Rebabbitting]

Originally Posted by Terry,NJ

One Tool and Die shop I worked in (Many years ago!) we used to ocassionally sharpen our blanking dies by holding them to the a 6" sanding belt. After one or two times on the sander, we would have to clean them up on a surface grinder. The sander is a quick fix. Not a good and proper answer. It is not over engineering to make two surfaces, intended to be flat and seal to be just that, flat enough to seal. The surface behind the belt is usually worn concave, especially at the rest, and incapable of producing a flat surface. And as Cape Codder and others have said, it must be 90 deg. to the carb mounting surface.
Terry

You are right Terry, Belt sanders do not any way, shape, or form make a good surface on a head, block, manifold, ect.

I remember when the belt sanding machines came out. They were billed as saving labor, but what they done is screwed up flat surfaces. I don't know any machine shops that I deal with would ever buy a New one if they are still available, not alone a used one.

The problem with a belt sander is the belt runs at one hight with no pressure on it. When the belt hits, say a head or anything, the belt then dips down under the surface that pushes the surface down a few thousandths, and after the belt comes up out from under what ever you are trying to surface, it goes back to its same hight.

So what you end up with, is a curve up under each end of what you were trying to surface. They are nothing but junk to a auto machinest that wants to do good work.

And as you said Terry, there is just no way to belt sand anything and keep it to the same position it was when New, a very poor practice.

[peters180a/170b]

I wish there was a place around here that will do it... part of N.Y. where i live there is 1 shop and i took it to him and he wanted nothing to do with it. So i used a lg. file and a leveler and worked out fine. I was lucky both manifolds were not that far off.

[Rex Perry]

Join Date: May 2010
Location: Rock Hill, S.C.
Posts: 941


Re: Manifold machining
Just for general information, I am posting a fixture that I made to do my own 'match milling' after I had a number of poorly done efforts at automotive shops. If you are not careful to make the carb mounting surface perpendicular to the manifold sedge when you match mill the intake and exhausts together. tha combination will not be vertical when installed and not fit the RS engine pan or fit the flare on the exhaust very well. Hand held grinding was NEVER correct when done for me that way.

In addition. I did NOT want a real smooth gasket surface as it makes the gasket easier to 'squirrel it's way out of the edges. I chose to use a fly cutter and adjusted the feed speed to leave just a very minor 'irregularity' so that the gasket would have a grip to the manifolds.

As always, this is just a thought.








RockHillWill,
Is there ever a problem with leveling the faying surfaces with your fixture? Looks like the four spacers at the stud mounts are for locating and serve no hold down function. Is that correct? From what I can see the manifolds are held down with two clamps at the top and the bolted attachment for the intake manifold. Are there others?
Thanks,

[RockHillWill]

Good morning, Rex

I just figured out your PM question. The timing was good, as I am getting ready to match mill two sets for a friend of mine who is restoring two Model A's at the same time, then I will be done with this fixture. I have gotten involved in another segment of the auto restoration arena, and most of my Model A fixtures are used less every day.

The intake and exhaust manifolds are bolted together as they normally are, then the intake is bolted to the support plate on the fixture (at the carb mount). This insures that the manifold mounting surfaces are 90 degrees to the carburetor so that it will be level in operation. Then the exhaust manifold is tightened down by the brackets that are shown on the top. Not clear in the posted pictures are the two lower support posts that are adjusted upwards to the bottom of the exhaust manifold, that then allows for those top brackets to 'squeeze' down on the exhaust manifold. The four support posts that are more visible are only used for alignment purposes. Because of the concern noted in an earlier post regarding the different heights for the exhaust and intake manifolds mounting areas, this allows for that dimension to be 'adjusted' after the match milling is done on the mounting side.

I spent quite a lot of time making this fixture after two poor experiences from having a 'machine shop' surface them on a belt sander. I found that I did not like the smooth surface for one thing, then noted that the edges of the manifolds around the perimeter had been rounded off by the operators errant hand movements, but the 'last straw' was that because the operator was unable to maintain a 90 degree hold on the combination manifolds, the exhaust pipe did NOT fit thru the cutout at the rear of the engine pan. To make matters worse, I was working on a fine point project and it ruined a VERY nice original #6 late '31 ribbed exhaust manifold.

Those that do not concern themselves with the aerodynamics involved in using engine pans to help cool down the radiator/engine or the desire to maintain the appropriate float bowl level will also not be concerned about this 'minor' issue of manifold work.

I hope this is what you were looking for in your PM request. If not contact me again, and I will do what I can to answer your question.

[Rex Perry]

Thank you for your comments.
As I understand it, there are two "adjustable" supports under the manifold below the hold down clamps. If I were to design such a support I would have it threaded into the base plate which would allow some vertical adjustment. Is that how you did it?
One other issue that needs some clarification has to do with the "adjustment" of the thickness of the mounting areas. It is unclear to me if the lugs of the manifolds are machined to achieve the same thickness on the intake and exhaust and what that would achieve.
Thanks again for your comments.
Rex

[RockHillWill]

It is my opinion that the original intake and exhaust manufactures were not able to control that mounting tab thickness, not only among their long production runs, but with different manufacturers involved I would assume that those dimensions were rarely the same among them.

It is also my opinion that to account for this Ford chose to use the 'spherical' design of the washers used between the intake and exhaust manifold bolt-down areas. By installing these washers in a manner that leaves the cup side of the washer towards the manifolds, it lets the radiused perimeter area make contact at the manifolds, while the outer contour of that thick washer allows for a small area to be 'normal' to the centerline of the stud allowing minimal side load on the nuts. This cupped design will flex to some degree on the heavy 7/16" studs providing the same type of anti-loosening that is afforded by lock washers.

So, the main concern regarding the relative heights of the intake to the exhaust manifold comes down to noticing the inside diameter clearance of the cupped washer to the manifold stud. The difference in manifold mounting tab heights will result in the cupped washer possibly not being installed with the washer i.d. not in line with the centerline of the stud. This is expected as that is the purpose of using the cupped washer.

If you install the cupped washer and cannot feel any 'gap' at either the intake or the exhaust manifold under the washer, you should feel comfortable in tightening the nut. If there is a gap, you might consider drilling out the hole in the cup washer slightly and check for the gap again.

I hope this is the info you were seeking.

As always, this is merely the opinion of one old man!

[Rex Perry]

RockHillWill,
I believe that you have provided the clarification that was needed. I will proceed with building my version of the manifold fixture. The initial use will be for an Autolite heater manifold but I do not, at this time, see a problem with mounting the other manifolds that were available.
Thanks again for your opinion. It is appreciated.
Rex

[mike657894]

I did mine with files and hones and straight edge. thought I had it licked as the smoke in the cab was gone. But while running some brake fluid through the carb. I had little puffs of white smoke out of port 1. The header isnt cut for gland rings which would probably fix up the minor leak. But I had put a few hours labor into the manifold. I am planning on buying a new manifold from snyders for 100.

[SeaSlugs]

Has anyone come up with a method to get it secured in a bridgeport for a one time run? I have access to one and not having good luck finding anyone locally that knows what their doing. Thought I could come up with a way to get it mounted but no need to if someones already invented that wheel. I have a few other manifolds that are borderline unusable due to saggage I could play with...

[Tom Wesenberg]

Originally Posted by mike657894

I did mine with files and hones and straight edge. thought I had it licked as the smoke in the cab was gone. But while running some brake fluid through the carb. I had little puffs of white smoke out of port 1. The header isnt cut for gland rings which would probably fix up the minor leak. But I had put a few hours labor into the manifold. I am planning on buying a new manifold from snyders for 100.

What's up with running brake fluid through the intake?

I'd never heard of that before.

[BRENT in 10-uh-C]

Originally Posted by SeaSlugs

Has anyone come up with a method to get it secured in a bridgeport for a one time run? I have access to one and not having good luck finding anyone locally that knows what their doing. Thought I could come up with a way to get it mounted but no need to if someones already invented that wheel. I have a few other manifolds that are borderline unusable due to saggage I could play with...

Yes, you can do it on a one-time shot if you have a large 2-3-4 block or a good quality angle plate, some machinist jacks, quite a few toe clamps and a few machinist C-clamps to anchor the silly thing down to the table firmly.

I have a similar set-up as what Will does however mine takes about an hour of fussing with it to get it indicated in where it is perpendicular to the carb flange, and level from one end to the other. My plate and fixture is lacking in rigidity where the flycutter must be moved at a very slow pace to keep the finish somewhat smooth on the manifolds. It does the job, however spending an hour or so 'babysitting' the powerfeed handle gets old quickly, and due to the interrupted cut of the flycutter and the harmonics from non-rigid fixturing, I don't dare walk away from it for fear of a crash. It has not happened yet, and I am not looking forward to that day!!


FWIW, I have more than a couple of vehicles that came in with carburetor drivability issues that were finally traced to manifolds that appeared to be "machined" with a belt sander that caused the carburetor to tilt. The only way that I can see how a belt sander could be correctly used is if someone had the bed of a long belt sander leveled in, and then mounting a fixture onto the carburetor flange that could check for level in two planes simultaneously during the sanding process so that it would have a chance at staying perpendicular to the ports.

[Terry, NJ]

Brent, Get a piece of i - 1 14" inches thick cold rolled steel a and have it skimmed on a Blanchard Grinder and use it for a base to the fixture. From then on, all you'll have to do is clamp it down on the table and go with it. Does your Bridgeport have a round crossarm, or a "Dovetail"?. Round cross arm can be hard to keep 0/0 sometimes. Tightening the locking bolts can throw the 0/0 off. so the guy might be in a hurry (Just this little govt job!) and not tighten it enough and especially with a interrupted cut, the whole head will move.
Terry

[DougVieyra]

Cape Codder, post #15:

I noticed your post on the "Manifold Surfacing" question, regarding your Auto-Lite heater cover, and not wanting to 'shave' it to fit your manifold.

Just so you know, all of the original after-market accessory "Auto-Lite" manifold heaters were either cast iron (mostly) or steel (not so common). At no time were the originals ever made of aluminum.

Starting about thirty-five or 40 years ago, a new reproduction of the original "Auto-Lite" cast-iron heater cover began to be made and sold - all of these later reproductions were made of cast aluminum and are still readily available today. The cast iron originals are hard to find, but do exist. But the later reproduction aluminum covers are quite common, cheap to purchase, and easy to buy.

So IF your Auto-lite heater cover (made for the waffle exhaust manifold) is made of cast-iron or steel, you have a legitimate concern to preserve a hard-to-find original item. However, as in 95% of the "Auto-Lite" covers I have seen on cars, if yours too is made of aluminum, then I would not let this later-made reproduction stop me from shaving it to fit your manifold.

- Wishing you the very best with your manifold heater, I remain with my best regards, Doug Vieyra